Can Vitamin D Help?

Studies of vitamin D’s ability to curb SAD have been mixed—some show a benefit, while others don’t. Proponents of vitamin D supplementation as a therapy for SAD note that many of the contradictory studies used doses that were too low or used D2, a form of vitamin D that is weaker than the recommended D3. A 2010 comprehensive review of existing studies that looked at the effects of vitamin D on different kinds of depression and anxiety concluded that treating vitamin D deficiencies in people with depression might be an easy and cost-effective way to improve mental health.

In another study, researchers from the University of Toronto noticed that people who were suffering from depression, particularly those with SAD, tended to improve as their levels of vitamin D in the body increased over the course of a year. Researchers, though, are unsure how much vitamin D is ideal. Still, it doesn’t hurt to make sure you’re getting what you can from your diet. Some studies suggest that as many as 7 out of 10 Americans don’t get enough of this “sunshine vitamin”—particularly during winter. The Institute of Medicine’s daily-recommended amount (for ages 1 to 70) is 600 International Units (IUs). Check with your doctor to see if you might need a supplement.